SB 931 
.M3 
Copy 1 



THE ANNUAL LOSS OCCASIONED BY DESTRUCTIVE INSECTS 
IN THE UNITED STATES. 



C. L. MARLATT, 

Asi^islant Entomolngixf, in ('iKtrge of Experimt'titid Firfd Work, 
Burroii of Eiitomolog!/. 



[Reprint from Yearbook of Department ok Acjrutltire for 1904.] 



o>' ^(^ 



CONTENTS. 



Page. 

Introduction 461 

Basis of estimates 46 1 

Results of control of in.sec;ts 46o 

The values of farm products and losses chargeable to insect pests 464 

Insect damage to cereal crops 465 

Insect damage to corn 465 

Insect damage ti > wheat 466 

Insect damage to hay and forage crops 468 

Insect damage to cotton 46S 

Insect damage to tobacco, truck crops, sugar cane, etc 469 

Insect damage to fruits 469 

Insect damage to forests 471 

Insect damage to miscellaneous crops 472 

Insect damage to cattle 472 

Insect damage to stored products 473 

Conclusion 474 



AUG 29 m? 

D. of a 



} THE ANNUAL LOSS 0( CASIONED BY DESTRrCTIYE 
INSECTS IN THE UNITED STATES. 

i 

yA By C. L. Marlatt, 

^ Assistant Entomologixt, in Clum/c uf Experimental Field Work, Bureau of Eutomulogii. 

IKTRODUCTION. 

In no country in the world do insects impose a heavier tux on farm 
products than in the United States. The losses resulting from the 
depredations of insects on all the plant products of the soil, both in 
their growing and in their stored state, together with those on live 
stock, exceed the entire expenditures of the National Government, 
including the pension roll and the maintenance of the Ami}' and the 
Navy. Enormous as is the total value of all farm products in this 
country, it would be very nuich greater were it not for the work of 
these injurious insects. The statistics of agricultural products for the 
year 1889, of the Twelfth Census, and for subsequent years, gathered 
by the Bureau of Statistics of this Department, indicate an annual 
value of all the products of the farm of about $5,000,000,000. To one 
familiar with the work of the im])ortant insect })ests of the different 
agricultural products entering into this total it is c()nn)arativel3' easy 
to ap})roximate the i^robable shrinkage due to insects. The detailed 
consideration of sueh shrinkages which follows indicates that they will 
rarely fall below 10 per cent, and in years of excessive insect damage 
may amount to 50 per cent or even more of the important staple 
products of the farm. An annual shrinkage of 10 per cent is a low 
estimate, which is more often exceeded than fallen below, and indicates, 
at current farm prices, a money loss of $500,000,000 — the nu'nimum 
yearl}' tax which insects lay on the products of the farm. This total 
comprises, however, only losses sufi'ered ))Y the growing and maturing 
crops and annually by live stock, and does not include two very con- 
.sideral)le and legitimate items, namely, the loss occasioned by insect 
pests to farm products, chieflv cereals and forage crops, in storage, 
and to natural forests and forest products. As shown in the consider- 
ation of these two sources of loss presented below, at least ^100,000,000 
nuist be assigned to each, making a total annual tax chargeable to 
insects of $700,000,000. 

BASIS OF p:stimate8. 

Throughout this paper the estimate of losses in dollars is based on 
the farm price of the crop actually harvested, and does not, therefore, 
take into account the possible reduction in value which would follow 
the marketing of the larger crop. While it is true that prices are 

461 



462 YEARBOOK <>F THE DEPARTMENT OF AGRICULTURE. 

regulated b}- production, the factor of distribution nuiv often pre- 
dominate, so that large crops in certain countries ma}' sometimes 
bring good prices and small crops low prices. During the last ten 
j-^ears, for example, the price of wheat in this country has exhibited 
little if any relation to our own production. The bumper wheat crop 
of 1901 of nearly 750,000,000 l)ushels brought to the farmer 23 cents a 
bushel more than the crop of 1891, which was 300,000,000 bushels 
less, or but little more than half the production of 1901; and this j^ear 
(1901) the farmer is getting nearly $1 a bushel for his wheat on a crop 
"arger than the average. 

Some definite means of estimating losses must be assumed, and any 
sffort to scale down these losses b\' reckoning possible enhancement of 
the market price in view of the conditions just cited would come more 
in the category of pure guesswork and be open to <|uite as great 
objection as the plan adopted. As an ollset to possibly enhanced 
values due to shrinkages occasioned by ins(H'ts. moreover, are certain 
very legitimate items of cost. A vei-y considerable item of loss 
properly chargeable to insects is the annual expenditure devoted to 
their control, which, except in the case of certain fruit and truck 
crops, has not been considered in the estimates. This amounts to a 
very considei'able percentage of the value of the crop in the case of 
orchard fruits, truck crops, and such field crops as cotton and tobacco. 
In the case of the cereals, protection is chieHy secured l)y farm 
practices, such as rotation of crops, variations in the time of planting, 
etc., and this also applies, to some extent, to cotton, tobacco, .and 
truck ci'ops. In estimating the losses due to the codling moth, for 
illustration, it is shown that over $8,000,000 a 3-ear is ex[)ended in 
spraying apple trees, allowing a cost of onh' 5 cents per tree. In the 
case of citrus fruits the cost of gassing and s}))'aying ranges from 5 
cents to $1.50 per tree. 

Another legitimate class of losses not inchidcd in the estimate is the 
.secondary losses which necessarily i-esult from diminished products. 
For example, the excessive reduction in winter wheat thi'ough the 
Hessian fly ravages in 1900 put a serious check upon milling opera- 
tions throughout the region worst affected and caused very heavy loss in 
this field of industry. Similarh' a shortage of cotton may so increase the 
values as to lead to the shutting down of cotton mills, as has been illus- 
trated recently. A shortage of gi"ains means a corresponding loss to 
the railroads and other ti-ansportation com[)anies and to shippers. In 
other woi'ds, any material shrinkage in an important product starts a 
train of losses to the end of the chapter, the total amount of which is 
((uite bej'ond calculation or estimate. 

The writer believes that these omitted items of loss will make good 
.'iny difi'erence of price which might result from the larger crops if 
insect damage were entirely eliminated. Outside of the cash value of 



ANNl'AL LOSS OCCASIONED BY INSECTS. 463 

the crop, furtliennore, is the actual material loss in products, ivhich is 
absolute so far as the consumer is concerned. The importance of this 
loss will vary with the nature of the crop. With perishable products, 
such as fresh fruits and vegetables, the losses due to insects may l)e of 
minor importance. Foi" example, if the apple crop were increased l)y 
25 or 50 per cent of marketable fruit, values would pro})ably shrink a 
correspoiidino- amount, and the demands of consumption and the pos- 
sibilities of storage ])e very greatly exceeded, so that there would 
actually ))e very little benefit, if any, to the producer. On the other 
hand, in the case of staple products of long keeping quality, as grains, 
cotton, sugar, luml)er products, etc.. the loss may t)e reckoned as more 
nearly conn^ilete. and the chief loss due to insects falls in this latter 
class. 

liESL'LTS OF COJsTltOl, OF INSECTS. 

Enormous as is the annual loss which may now be fairly charged tc< 
insects, it would undoubtedly be vastly greater if such pests were left 
absolutely unchecked and no eti'orts were made to limit their opera- 
tions. Wer(> it not for the methods of controlling insect pests, result- 
ing from the studies of the Bureau of Entomology and of the official 
entomologists of the \aiious States, and the practice of these measures 
by progressive fai'iners and fruit-growers, the losses froiu insects would 
be greatly increased. Familiar illustrations of savings from insect 
losses Avill occui' to anyone familiar with the work in economic or 
applied entomology in this country. The cotton worm, before it 
was studied and the luethod of controlling it l)y the use of arsenicals 
was made common knowledge, levied in bad years a tax of i^30,000,000 
on the cotton ci'op. The prevention of loss from the Hessian liy, due 
to the knowledge of proper seasons for planting wheat, and other 
direct and cultural methods, r(\sults in the saving of wheat to the 
farm value of from ^l()0.()i)U,0(iO to $200,000,0(10 annually. Careful 
statistics show that the damage from the codling moth to the apple 
is limited two-thirds l)y the adoption of the arsenical sprays, band- 
ing, and other methods of control, representing a saving of from 
$15,000,000 to 55 !>(),( 100,000 in the value of this fruit product alone. 
The existence and progress of the citrus industry of California were 
made possible by the introduction from Australia of a natural enem\' 
of the white scale, an insect pest which was rapidly destroying the 
orange and lemon orchards, this introduction representing a saving 
to the people of that State of many million dollars every year. The 
rotation of corn with oats or other crops saves the corn crop from 
the attacks of the ro(jt worm to the extent of perhaps $100,000,000 
annually in the chief corn-producing regions of the Mississippi Valle}. 
The cultural system of controlling the boll weevil is already saving 
the farmers of Texas many millions of dollars, and, in fact, making the 
continuance of cotton growing possible; and scores of similar illustra- 
tions could be cited. 



4fi4 



YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 



The lo.sses occa!-;ioned bv insects to farm products exhibit a wide 
range in dift'erent years, due, as a rule, to favorable or vuifavoral)le 
climatic conditions, and also to the abundance, from time to time, of 
natural enemies. The result is more or less periodicity in the occur- 
rence of l)ad insect 3'ears. In other words, periods of unusual abun- 
dance of particular insect pests are, as a rule, followed l\y a number 
of years of comparative scarcity. Furthermore, seasons which may 
be favorable to one insect may prove unfavorable to others, hence 
there may be not only periodicity in the occurrence of the same insect, 
l>ut more or less of a rotation of the different insect pests of particular 
ci'ops. 

THE VALUES OF FARM PRODUCTS AND LOSSES CHAR(4EABLE TO INSECT 

PESTS. 

In the table following, the value of certain fai-m products, namely, 
the cereals, ha}", cotton, and tobacco, is based on the reports of the 
Bureau of Statistics of this Department for 1904. The other values 
are taken from the census tigures of 190(>. The values assigned to 
farm products are given in round numbers for convenience in citation, 
and allied products are thi'own together to get a more compact and 
readily understood statcMuent. The last two colunms, indicating the 
shrinkage due to insect work, are based on the crop actually harvested — 
that is to say, except for such damage the crop would have been 10 or 
20 per cent greater. It will be noted also that the total value of farm 
products is greater than that given in the opening paragraphs of this 
article. This is accounted for by the fact that for the purposes of 
this table, indicating insect damage, no subtractions are necessary to 
represent the farm products consumed by live stock, inasnuich as the 
damage due to insects is to the growing and maturing crop, and the 
losses indicated for the ci'()]>s and for animal pi-oducts are independent. 

Annual rahie.i of farm products and losses chargeable to insect pests. 



Percent- j 

age of Anioutit ofloss., 
loss. 



Cereals 

Hhv 

Cotton 

Tobaceo 

Truck crops 

Sugars 

Fruits 

Farm forests 

Miscellaneous crops . 
Animal products 



12.000,000,000 
.'.80, 000, (X)0 
tlUO, 000, 000 

53, 000. 000 
•Mr,, 000, 000 

oO.OOO.fKW 

i;«,ooo,ooo 

110,000.000 

58, 000, 000 

1 , 750, 000, 000 



9200, 
53, 

00, 



27, 

n, 

5. 
175, 



000,000 
000, 000 
000, 000 
300, 000 
000, 000 
000,000 
000,000 
000, 000 
MOO, 000 
000, 000 



Total 

Natural forests and forest products. 
Products in storage 

Grand total 



5. 551 , 000. 000 



595 
100, 
100 



100,000 
000.000 
000,000 



795. 100, 000 



ANNUAL LOSS OCCASIONED BY INSECTS. 465 

INSECT DAMAGE TO CEREAL CROPS. 

Oiil}' the losses to the two more important cereals, corn and wheat, 
will be discussed in this paper, as the injury to oats, barley, rye, etc., 
will average about the same percentage and need not be specifically 
analyzed. 

INSECT DAiMAGE TO CORN. 

In point of quantity and value corn is the leading cereal crop of 
the United States. Its annual farm vahu^ in later years has nearly 
equaled and sometimes exceeded $1.00<»,0(H).(H)0. While less suliject 
to insect damage than wheat, the next most important cereal, the corn 
product would be considerably greater were it not for important insect 
pests. The work of several of these is obscure, and many farmers are 
entirely ignorant of the existence even of some of the worst enemies 
of this crop. In this last category falls the work of the corn root 
worm {D'tahrottcd loiigiaynils)^ which ordinarih^ passes unnoticed, or at 
least is often misunderstood. The larva of this insect feeds on the 
roots of young corn, and in regions of bad attack may cause an almost 
entire loss of the stand. The corn root worm, together with one or 
two allied species wK)rking in substantially the same way, causes an 
annual loss of at least 2 per cent of the crop, or some $20,000,000. 

Perhaps the next most important insect pest of this cereal is the boll 
worm or ear worm. This insect, as shown l)y Mr. A. L, Quaintance, 
special field agent of this Bureau, probably attacks from IHl to 100 
per cent of the ears of sweet corn throughout the country, and in the 
South practical I3' an equal percentage of the ears of field corn, as 
shown by actual counts in the field made during the ^ears 1902 and 
1903. The average loss in the number of kernels to an attacked ear is 
15 per cent, or, if allowance be made for the smaller size of the termi- 
nal kernels, at least a loss of 7i per cent. The percentage of loss is 
less in the great corn areas of the Northern and Middle States, but a 
•2 per cent loss for the United States chargeable to this insect is cer- 
tainly well within the limits of actual damage, and would, for the corn 
crop of 1904, indicate a loss of over $20,000,000. 

Of perhaps equal importance to this crop are the depredations of 
the chinch bug. Chinch bug injury is, as a rule, more marked where 
corn is grown in the neighborhood of wheat or other small grains, and 
in such cases the migration of the chinch bug from wheat to corn may 
often result* in the total destruction of considerable areas of corn. 
The chinch bug is a strong flier also, and at the period of migration in 
midsummer corn is often attacked, the loss in the case of this cereal 
being, however, very much less than in the case of wheat. For the 
country as a whole, however, the loss from the chinch bug, taking one 

1234 A1904 30 



466 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 

year with another, will probabl}' be 2 per cent of the crop, or, esti- 
mating from the crop of 3904, 120,000,000. 

Every year in ditierent sections of the country there is notable 
injury to corn hy such insects as bill -bugs, the various wireworms, 
cutworms, and army worms, stalk-borers, various species of locusts 
or grasshoppers, corn plant-lice, and other insects, to a total of fifty 
fairly important species. These minor pests undoubtedly cause a loss 
of an additional 2 per cent, making a total annual injury of 8 per cent, 
and indicating a loss of $80,000,000. 

INSECT i)A.M.\(;K TO WHEAT. 

Of the cereal crops of this country wheat sutl'ers most from insect 
depredations. Of the large number of insects which depredate on 
this cereal, the throe important species are the Hessian tly. tiie chinch 
bug, and the grain })hint-lou.»e. using the latter term to include several 
allied species which work in nmch the same manner. The chinch l)ug 
is n()tal)ly a wheat pest, although its damage to other cereals and forage 
crops is very considerable. The losses from the depredations of this 
insect on wheat in single States have ranged between ^J(i,ooo,0(Mi and 
$20,000,00(1 in one year. A \(M-y reasonable average amuial estimate 
of loss, taking the country as a whole, would be .") per cent of the value 
of the wheat crop, which would indicate about $20,000,000 a year 
chargeal)le to this insect. 

The Hessian tly is distinctly a wheat pest, although doing some dam- 
age also to rye and barley. The losses due to this insect will be 
considcMed nioie in detail to indicate their nature specitically and to 
illustrate the exactness and I'cliability whicli may sometimes charac- 
terize records of this kind relating to particidar pests of a single crop. 

The season of ItMJO is notable in Hessian-Hy annals as exhibiting the 
most destructive work of this })est in recent years. The fly was very 
generally ju'esent throughout the main wheat-growing districts of the 
Ohio and Mississippi valleys, but its ravages were this 3'ear con- 
centrated particularly in Ohio and Indiana. The statistics of the acre- 
age and yield of wheat and value of the crop for this year for the 
States mentioned reflect very plainly the loss occasioned by this pest. 
The wheat area in these two States in 1900 and the years inunediately 
preceding was about 5.000,000 acres. Chi(>tly on accoimt of the rav- 
ages of the Hessian fly more than half of this acreage (2,577,000 acres) 
had been abandoned and planted to other crops prior to May 1, 1900, 
as shown by the records collected by the Bureau of Statistics of this 
Department. The al)andonment was about 40 per cent for Ohio and 60 
percent for Indiana. The cost of the pre])aration of soil, planting, and 
seed wheat for this abandoned acreage is all that need be reckoned, inas- 
much as it was possible to use the land for other crops, such :is corn 
or oats. The loss in labor and material indicated will approximate 



ANNUAL LOSS 0CCASI0NP:D HY INSECTS, 467 

$3.50 per acre, giving- a total of over $9,000, 00<). Of the remaining 
wheat acreage, the average yield per acre for this year in Ohio was (> 
bushels as against 15.3 bushels for the year following, H.2 bushels 
for the year previous, and nearly 17 bushels for the years 1<S97 and 
1898. For Indiana, the yield per acre in 1900 was only 5.3 bushels as 
contrasted with 15.8 bushels for 1901, and 15.6 and 9.8 bushels, 
respectively, for 1898 and 1899. In other words, a decrease in the 
3^ield per acre is shown of nearly two-thirds, for these two States, for 
the area in wheat which was left for harvesting. The Hessian fly does 
more or less damage every year, which reduces the average yield per 
acre, and, therefore, if such damage be eliminated, the average yield 
per acre should be in the neighborhood of 15 bushels, indicating a loss 
for this year from the Hessian fly of nearly 10 bushels per acre for 
the area harvested, or, for the two States, of 21,230,000 bushels ol 
wheat, of approximately a farm value (at the low price for that year) 
of $15,000,000. This loss, combined with the $9,000,000 indicated for 
the abandoned acreagxi, gives a total direct loss for these two States of 
over $21,000,000. These figures, enormous as the}' are, are l)ased on 
the careful statistical records of the acreage, yield, and prices of 
1900 collected by the Statistician of the DepartuKnit, \\ orking entirely 
independently of the Bui'eau of Entomology. 

During this year the damage in other wheat-producing States was 
notable. For example, more than 20 per cent of the planted area of 
Michigan was abandoned, and lesser amounts in other States, with 
great shrinkages in the yield of acreage which was actually harvested. 
The loss, therefore, for this single season, due to the Hessian fly, 
undoubtedly approached $100,000,000. 

The losses occasioned bv this insect, while showing great fluctua- 
tion, as indicated above, are an amuial tax on the wheat crop. Except, 
in cases of exceptional severity they pass, however, comparatively 
unnoticed. For example, the Hessian fly is not being especially 
complained of this year (1904), yet the agent investigating the insect 
enemies of cereal crops in the Ohio valley reports that many flelds 
show injury to the extent of from 50 to 75 per cent. In compara- 
tively few years does this insect cause a loss less than lo per cent of 
the crop, or the equivalent of a shrinkage of over 50,000,000 bushels 
in the yield, or. on the valuation of the ci'op for 1904, of over 
$40,000,000. 

The losses due to wheat plant-lice are often very considerable, 
resulting in a heavy shrinkage of wheat at the moment of maturity, 
when the wheat heads may be covered with these lice, sucking away 
at the soft, forming kernels. The yield of badly infested flelds may l)e 
reduced at this time from 25 to 50 per cent, and when weather condi- 
tions are favorable this pest is often altundant over enormous areas. 



468 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 

The annual loss occasioned by wheat plant-lice probably does not fall 
short of 2 or 3 per cent of the crop. 

The many other insects depredating on wheat, including grasshop- 
pers, the wheat midge, several species of sawflies, and the cutworms 
and army Avorms, will swell the total of loss to at least 20 per cent of 
the crop. In other words, were it not for the attack of these pests 
the wheat crop would be one-fifth greater than it now is, or have an 
additional value of approximately $100,000,000. 

The insect damage to other cereal crops pi-obably falls short of 10 
p(M' cent. A 10 per cent average, however, for all the cereals, is cer- 
tainly a reasonable one and is th(» biisis of the loss indicated in the 
g(Mi('i'al table. 

INSECT DAAIAGE TO HAY AND FORAGE CROPS. 

The damage t)y desiructi\e insects to hay and forage crops is more 
obscure and h^ss generally understood than in the case of any other 
fai'm |)roducts. Certain of the larger insects depredating on hay and 
forage crops are commonly known. These include the various specie^ 
of locusts or grasshoi)pers, army worms, and cutworms. Ver}^ little 
understood and generally overlooked, however, are the webworms and 
small grass woi-ms iC/-a//thi/,s spp.) which woi"k about the base or roots 
of the plants, and which are so al)undant that at the propei' season 
the moths flit n\) in front of one at every step. Swarming also in grass 
lands are man}' sj)ecies of minute leaf-hoppers which reduce the yield 
enormously, their small size being more than offset by their preva- 
lence and numbers. Obscur(% l)ut ver}- important also, are the white 
grubs, which work on the roots and often kill the grass outright over 
large areas, and everywhere tax production c()nsidera})ly. In the 
same class in lKil)it are the meadow worms or leather jackets, the grass- 
root feeding larvse of the crane flies. A 10 per cent shrinkage from 
these and other pests in grasses and forage plants is a minimum 
estimate. 

INSECT DAMAGE TO COTTOX. 

The principal insect depredators on cotton are the cotton boll weevil, 
the boll worm, and the leaf worm. Alany other insects, however, 
inflict minor damage. The loss chargeable to the boll weevil, from 
the very conservative estimate of Mr. W. D. Hunter, the agent charged 
with the study of this insect in Texas, represents, for the year 1904, 
some 120,000,000. 

The })ollworm is chiefly destructive in the southwestern cotton- 
producing States of Mississippi, Indian Territory, Oklahonia, Arkan- 
sas, Louisiana, and Texas, and causes a damage in these States of 
from 2 to 60 per cent of the crop. East of these States compai'atively 
little damage is done by this insect. The damage for the States first 



ANNl^AL LOSS OCCASIONED MY INSECTS. 469 

inentioued, where this insect is most injurious, has been very eonser- 
vatively estimated ])y Mr. A, L. Quaintanee at 4 per cent of the crop 
of these States, and indicates an annual loss of some $12,000,000. 

The cotton leaf worm in years of excessive damage, before the use of 
arsenical poisoning- was a common practice, caused a loss of $20,000,000 
to $80,000,000. The present damage resulting from this pest is very 
much reduced, but with the increased acreage of cotton an annual loss 
of from $5,000,000 to $lo,()O0,(M)<» may be conservatively estimated. 
Without counting the losses due to many minor insect depredators, we 
have already a total loss of more than $4(»,iHH»,()()0 chargeable to three 
important insect pests of this staple. 

INSECT DAMA(iE TO TOBACCO, TRUCK CHOI'S. SUCAR CANE, ETC. 

Detailed statements relative to the insect losses to the crops enume- 
rated above will not t)e attempted in the space at command. All of 
these crops are subject to the attacks of important insect pests, and a 
reasonable estimate of the annual damage is 10 per cent of the value 
of the first and last named cro])s, and fully 20 per cent in the case of 
truck crops. Vegetables and other truck crops are especially subject 
to insect injury, and. furthermore, in th(^ case of these crops there is 
always a large expenditure in the control of ins(^cts, the items of actual 
damage and cost of control togc^ther probably making the tax due to 
insects double the noi'mal lo per cent late. 

INSECT I)AMA(;e to fkitits. 

The orchard and small fiuits sutler heavily from insect pests, both 
directly and Ixn-ause of the ex})ensive methods of treatment necessary 
to prevent still greater losses. The examination of this subject will 
be limited to the insect injuries to the apple. There are several hun- 
dred insects which dejjredate on the roots, truid\, foliage, and fruit of 
the apple. r\\o impoi'tant pests art^ the woolly aphis, injuring the roots; 
the trunk and lind) boicrs; the leaf worms, canker worms, and tent 
caterpillars; and the various scale insect pests, including the San ,Iose 
scale. Injuring the fruit are the codling moth, tlie curculio, and the 
apple maggot. It is a very difficult matter to estimate the amount of 
loss chargeable to these various insects. Those affecting the health 
and vigor of the tree itself lessen the productiveness at least 17 per 
cent, estimating 5 per cent for the woolly aphis, 2 per cent for borers, 
and 10 percent for the plant-lice, scale insects, and caterpillars and 
other leaf depredators. 

Very notable injury to the fruit also results from the work of the 
cui-culio and the apple maggot, but space will be taken merely to dis- 
cuss somewhat in detail the injury chargeable to the codling moth. 
This species probal)ly causes a greater monetary loss than any of the 
other enemies to fruits. Various estimates of the loss due to its attacks 



470 YEARBOOK OF THE DEPAETMENT OF AGRICULTURE, 

have been made, and in oeneral it i.s believed that roujihiy it causes a 
loss of from one-fourth to one-half of the apple crop of the United 
States every year. Mr. C. B. Simpson, while special field agent of 
this Bureau, gave some of the recent estimates of losses in various 
States: 

In 1889 Profesi80i' Forlx-s reached the concUision that the annual los8 in the State 
of UUnois was $2,875,000. It is estimated that in 1892 the insect caused $2,000,000 
loss to Nebraska apple growers. Profe.«sor Slingerland estimates that in 1897 the 
insect taxed the apple growers of New York $2,500,000. In 1900 one-half of the crop 
of Idaho was damaged, while in 1901 the loss was much greater. ^Ir. Ah-Pherson 
estimates that in I<lali() the loss in 1902 was $250,000. * * * In many sections of 
the Pacific Northwest the loss was from 50 to 75 per cent. 

An estimate made Ilv Mr. Simj)s(>ii and the writer" is perhaps as 
nearly accurate as may l)e in indicating the (juantity lost in barrels of 
merchantat)le apples. The ))est availal)le estimates of the a[)ple crop 
of the United States sue those compiled by the American Agricultur- 
ist, and from these it is found that the average crop for the five years 
from 18i»S to 1902 was 4T.0(i(i.O(iij barrels. This includes oidy apples 
of first and second (piality. 

It has l)een shown by careful observations in various apple-growing 
States that the codling moth, as already indicated, may cause a loss of 
from i;o to 4:0 per cent of fruit which would otherwise be sound and 
merchantable. For reasons to l)e given later on, in computing the 
actual moiK^tary loss to the apple growers of this country by the cod- 
ling moth, we prefer to take the lower of these two estimates. This 
20 per cent decrease in merchantalde a|)ples would represent some 
12.000,000 barrels, and at an average profit of $1 per barrel indicates 
a loss of $12,000,000, less the value of this fruit for cider pur})oses, 
supposing that it is all so used. The average pi'ice for cider ai)ples 
will not exceed 80 cents ])er barrel, which would rejiresent a reduction 
of 13,600,000, leaving a net loss of §8,-1-00,000. The loss throughout 
the country in small orchards supplying local needs luidoubtedly 
averages much higher than in the large conmiercial orchards, which 
supply the bulk of the fi'uit to the markets. The estimate made b}' 
Mr. Simpson of the loss in such home orchards is $3,000,000, which, 
added to our former figures, gives a total direct loss to the apple crop 
annually from the codling moth of $11,400,000. 

One woidd be perfectly justified in estimating the tictual loss in 
merchantable ap})les at a nuich higher figure than 25 per cent, and an 
average might be assigned of 35 or 40 per cent at least, which would 
have very greatly increased the apparcMit monetary loss. There are, 
however, considerations which ofiset the monetary loss occasioned by 
the codling moth and undoubtedly reduce it very considerably. The 
apple is a peri.shable fruit and must be consimied within a limited 

« Bulletin No. 41, Division of Entomology, The Codling Moth. 



ANNFAL LOSS OCOASIONKD BY INSECTS. 471 

period. It is not litce wheat and other cereals, the standard grades 
of which have fairly tixed values and which may be kept indetinitel} . 
The cold-storage system has verj' much extended the luarketing period 
of apples, but this aflects onl}' a limited amount, measured by the 
actual cold-storage capacity, and the bulk of the crop must find an 
immediate market. Therefore, if the additional fruit Avhich is now 
rendered unsalable ))v the codling moth should be thrown on the market, 
the actual i)rice of apples would pro])at)iy be affected even more than 
the inci'eased supply would indicate. The increase in our export apple 
trade, which is being actively encouraged liy the Department of Agri- 
culture, and the devclopniciit of cold-storage facilities for fruit will 
undoubtedly increase the market for api)les from year to year. Never- 
theless, one is warranted in taking the lower estimates considered 
a])ove, in view of the ])robable decrease in prices which would result 
if the codling moth damage did not materially reduce the crop everj' 
year. 

An additional and impoi'tant item of loss is the annual charge for 
spraying oi- otherwise^ treating apple trees, without which, as indicated 
above, the losses fi-om the codling niotii and curculio woukl be doubled 
if not trebled. Practically all commercial apple oi'chards are spi-aved 
annually with arsenicals. and banding of trees and other means of pro- 
tection an> also pi'acticed. Of the 20(),0()0.(mi(i api)le tnnvs eiuunerated 
in the last census, on the authoi-ity of Mr. Taylor, at least KJ."). 000, 000 
are in bearing condition, and the cost of s[)raying and other treat- 
ments for these will range between T) and lo cents per tree. As an 
offset to untreated orchards, the lower estimate of cost may be taken, 
namel}', 5 cents per tree, which gives a charge for treatment of 
$8,250,00»». Comtiining the direct shrinkage or loss and the cost of 
protection from still gi'eater loss gives a total tax chargeable to the 
codling moth of nearly ^20,000,000. 

The insect losses to other deciduous fruits are <juite as heavy as in 
the case of the ap})l(\ and especially when the tr(>atments for the San 
Jose scale and other scale pests are considered: and in the case of cit- 
rus fruits the cost of treatment is nuich greater and the actual losses 
again heavy. We are warranted, therefoi-e, in placing the loss to 
fruits from insect pests as high as 2o per cent annually. 

INSECT DAMAGE TO EOKESTS. 

The valuation of farm forests, namely, planted forests of artilicially 
wooded areas on farms, is given in the last census at $110,000,000. 
A brief considei'ation of the numeious insect pests of such plantings, 
including the boi'ers — which often almost utterly destroy the trees, as 
in the case of the black locust — the leaf defoliators, and many other 
varieties of depredating insects, indicates that a 10 per cent annual 
loss of such plantings is not an unreasonable estimate. 



472 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 

Of very much greater significance and economic importance, how- 
ever, is the insect loss to natural forests and to wood, lumber, and 
manufactures. The annual losse>-? occasioned b}- insect pests to such 
forests and forest products have been estimated b}'^ Dr. A. D. Hopkins, 
special agent in charge of forest insect investigations, at not less than 
$100,000,000. This is based on late stumpage values and on the whole- 
sale prices of the conmiercial products; in other words, it covers both 
the losses from insect damage to standing timber and to the crude and 
manufactured forest products. The annual loss to growing timber 
is conservatively placed at $70,000,000. This represents a loss of 
$20,000,000 annually to hardwood timber, as indicated by Doctor Hop- 
kins in his article in the Yearbook of this Department for 1003, and 
$50,000,000 annual loss to coniferous forests. As a single illustration 
of the loss in the last category may be mentioned the destruction in 
the year 1002 of 600,000,000 feet of valuable timber in the l^lack Hills 
district, representing a cash loss of upward of $25,000,000 in one lim- 
ited an^a. The damage by insects working in lumber and manufactures 
of wood is very consideral)le. and has recently been estimated by 
Doctor Hopkins to represent a miiiinuun aiuuial loss of 5 per cent of 
the valuation of such products, amounting to some S30,000.000 and 
completing the total of Slt»0.<iO(i.(iO() already indicated. This loss is in 
addition to the loss to farm forests referi'ed to. 

insp:( r damaok to mischi.lankois chops. 

A great many minor cro})s enumerated in the census of 1000 cannot 
be discussed separately, and the valuation of these crops is lumped 
together and a 10 per cent loss chai'geable to insects estimated on the 
whole, which seems reas()nal)l(» in view of the examinations already 
made of the more impoi'tant fai-m j)i'odu(ts. 

INSECT i>a>ia(;h to cattle. 

The losses due to biting and parasitic insects of cattle are consider- 
able. The principal (•ul})rits are the ox warble and various biting tlies 
and ticks. The damage chargeable to the ox warrble was very care- 
fully investigated several years ago by a western farm paper, and from 
the averages reported from the chief cattle States of the Mississippi 
Valley it was shown that 50 per cent of the catth^ received in the Union 
stock yards at ('hicago during the grubby season (from January to 
June) were infested and more or less injured by the presence of the 
larvae of this insect. The depreciation in the value of hides and the 
lessened quantity and poorer (juality of the beef indicated a total loss 
during the season in (juestion of over $8,000,000. This loss applies 
only to the cattle coming to the Chicago market during the period 
mentioned, and is merely an indication of the much greater loss to 
range and farm stock throughout the countrv from this one pest. The 



ANNUAL LOSS OCCASIONED BY INSECTS. 473 

loss for Great Britain from the warble has been estimated to var}^ from 
$10,000,000 to $35,000,000 per annnm, and the total for the United 
States certainly can not fall below that for Great Britain. 

The shrinkage or check to fattening due to the annoyance from 
biting flies and other insect pests of cattle represents a ver}' consider- 
able total ever}^ year, probably, in view of the greater prevalence of 
these pests, much more than is chargeable to the ox warble. 

Horses, sheep, and other farm animals are subject to the attacks of 
similar parasites and other insect enemies, and if all these be consid- 
ered, including, for example, the buffalo gnats, often ver}' destructive 
in the South, the many gadflies, botflies, the screw-worm fly, and such 
parasites as the ticks and lice, a heavy percentage of loss must ])e reck- 
oned. A 10 \)ev cent annual loss has been assigned, certainly a con- 
servative estimate, which represents a shrinkage in stock values due 
to insect pests of ^175,000,000. 

INSECT DAMAGE TO STORED PRODUCTS. 

The estimates given in the foregoing ivlating to vegetal)le products 
give the shrinkage due to the attacks of insects to the growing and 
maturing crops. After these crops have run the gauntlet of insect 
enemies during their entire period of growth — and this applies notat)ly 
to the cereal and forage crops and to tobacco and certain truck crops — 
they arc still sul)ject to the inroads of another class of insect depre- 
dators while in storage on the farm, or, in greater accumulations, in 
elevators and mills, or, again, while in transit, especially in the case 
of long shipments l)y sea. The cereals are all kept in storage until 
consumed, which means a considerable period for the bulk of the crop. 
The various grain weevils and beetles, flour moths, and other insect 
pests which depredate on stored grains frequently cause great losses, 
and an estimated injury of 5 per cent is a reasonable and probably 
minimum figure. Computing this percentage, therefore, on the valua- 
tion of the cereal products for 1904, we have indicated an annual loss 
of 1100,000,000. 

The location of food products for human consumption is in the 
house storeroom and kitchen, and often this last opportunity for insect 
damage is improved by various species of the stored-grain ])ests 
already referred to. Animal products are attacked by larder beetles, 
ham beetles, etc., fruits by various fruit and vinegar flies, and the 
woolens or the household furnishings by carpet beetles, clothes moths, 
silver fish, etc. 

Cured tobacco is especially subject to insect attacks and damage, the 
most important source of injury being a minute insect known as the 
cigarette beetle, which not only eats into cigarettes, but all other forms 
of cured tobacco. It is now widespread in America, occurring in 



474 



YEARBOOK OF THE DEPARTMENT OF AGRK 



021 486 495 2 



practically all factories, warehouses, and retail establishments, and is 
frequently the cause of very heavy losses. 

In the general table a total loss of $100,000,000 is indicated for 
insects attacking stored products. This is covered by the loss indi- 
cated for cereal products alone, and if the other items of loss just enu- 
merated were included a considerable increase in the estimate could 
legitimately be made. 

CONCLUSION. 

A general analysis of the insect losses for this country has been given 
in the introductory paragraphs. In concluding it is only necessary to 
emphasize again the fact that these losses, enormous as the}" are esti- 
mated to be, could he legitimatel}' swelled by adding the secondary 
losses which, in the case of the great staple productions of the farm, 
follow any considei'a))le shortage and ultimately add to the cost of 
living for every indi\idual, in addition to creating large commercial 
distur})ances. Furthermore, the cost of protection from insect damage 
has been considered only in the case of one or two products of the farm. 
Another considerable insect tax not estimated for is the direct loss and 
the cost of protection from domestic or household ins(>ct pests. Screen- 
ing of houses against mos(|uitoes or Hies, protection from roaches, 
clothes moths, and the lavages of the white ant and of various parasitic 
insects, ai'e a charge on every hous(»hold. The white ant in Washing- 
ton, n. ('.. alone causes losses of thousands of dollars yearly, and it is 
nuich nior(^ destructive^ in southern districts. If the smaller or larger 
sums ex])en(led for protection from such pests were tabulated for the 
whole countiT. the total would probably exceed ^50,000,000, and might 
be double that amount. An omission perhaps more important than any 
of these is the indii'cct loss to the produ''ing and earning capacity of 
connnunities l)y diseases conveyed b}' insects. For example, malaria 
and yellow fever are dependent solely on certain species of mosquitoes, 
find typhoid fever is conunonly carried, as shown by Dr. Howard, by 
house flies. The losses from all three of these diseases are enormous, 
and ill the case of yellow fever outbreaks, often almost ))eyond compu- 
tation. With domestic animals the tick, responsible for Texas fever 
in the South, has been (\stimated to cause an aiuiual loss of $100,000,000, 
and other diseases of man and domestic animals will undoubtedly 
be shown to depend exclusively or largely on biting or other insects. 
In view of these omissions, the writer is convinced that the total of 
over $7<*o,00ti,(i(Mi annual loss assigned to insect pests in America is 
below rather than al)ove the actual damage. The lessening or preven- 
tion of this loss is the problem foi" the economic entomologist to solve. 



